The invention relates to a ground effect vehicle, that is, a vehicle having means for inducing negative lift.
It is known to shape the undersurface of the body of a racing car and to provide the car with longitudinally extending skirts at its sides, in such a manner as to define a venturi duct between the body and a road surface over which it moves, so that the flow of air between the car body and the road surface tends to increase the contact loading of the car to the surface. This so-called "ground effect" depends on the shaping of the undersurface and the skirts so that the air flow in the venturi duct has a velocity everywhere greater than at the airflow exit at the rear of the car. The air consequently has a lower pressure everywhere in the duct than at the exit. This low pressure acts on the undersurface of the car body to generate negative lift. The downward or negative lift component of force acting on the car body is transmitted through the suspension and the springs so as to increase the grip of the tires on the road. The effect is also to reduce the induced drag of the car, with a consequent reduction in the energy employed in moving it.
It is a disadvantage of such an arrangement that the aero-dynamic characteristics dictated by the undersurface shape are affected by its relationship to the road surface, which continuously changes during cornering, acceleration and braking loads. Moreover, the suspension characteristics of the car are changed because they must absorb and transmit the aero-dynamic loads. The design of the skirts provided at the sides of the car to help define the venturi duct is complicated by the need to accommodate considerable movements between the vehicle body and the road surface.